The invention is directed to testing telecommunications access circuits and has particular application to transfer engineering testing prior to transfer of service from an old technology network to new technology network.
There is an increasing trend to transfer telecommunications traffic from old technology networks to networks based on new technology such as Internet Protocol (IP). BT's 21CN is an end-to-end IP-based network replacing complex old-technology network and systems infrastructure to provide faster, more efficient and more cost-effective delivery of converged services. The transfer process is often referred to as “transfer engineering”.
FIG. 1 shows part of a conventional, 20CN telecommunications network of the type that is suitable for replacement with new technology. The 20CN telecommunications network of FIG. 1 comprises a first, 20CN access network 200. 20CN access network 200 connects between main distribution frame (MDF) 10 and into the pubic switched telephone network (PSTN) 300 for connecting voice calls. In addition, access network 200 has a connection into an internet service provider network (not shown) for broadband connections.
MDF 10 is an integral part of a telephone exchange or central office and is divided into two sides. On the subscriber or D-side, the MDF provides terminations for cables connecting to telecommunications terminal equipment, 30, 40 located at the user's premises (e.g. telephone apparatus 30 and computer 40—connected via a broadband DSL connection to be described later). On the exchange or E-side, MDF 10 provides terminations for cables for connection to a telephone switch or other: communications service provider equipment—depending on whether it is a broadband (DSL) or narrowband (POTS voice band) circuit. Users are connected to the appropriate piece of service provider equipment by manually connecting a jumper wire between the user connection on the D-side and the appropriate service provider equipment connection on the E-side.
As shown in FIG. 1, MDF 10 comprises standard E-side connection points 80, 90. In the 20CN access network, standard connection point 80 is patched in the MDF 10 to the D-side narrowband connection to the user's telephone apparatus 30 and is dedicated to providing a narrowband service to the user.
E-side connection point 90 is patched in the MDF 10 to the D-side broadband connection to the user's computer 40 and is dedicated to connecting a broadband service to the user.
Turning now to the network side of MDF 10, connection point 80 on MDF 10 is connected to the 20CN access network for voice services via Remote Concentrator Unit (RCU) 210. RCU 210 concentrates a number of analogue local user lines digitises them into IP packets which are then concentrated to provide a multiplex connection to 20CN Digital Local Exchange (DLE) 220.
Connection point 90 on MDF 10 connects to digital subscriber line access multiplexer (DSLAM) 230. In a similar way to RCU 210, DSLAM 230 concentrates a number of connections, in this case broadband (i.e. DSL) connections, from a plurality of users onto a multiplex connection to Broadband Remote Access Server (BRAS) 240. BRAS 240 forms an interface from the 20CN access network to an internet service provider network (ISP), i.e. providing internet access to the user via a broadband connection. It is noted that the broadband connection at connection point 90 is also connected to RCU 210 via another port on DSLAM 230, the D-side of MDF 10 and a second connection at E-side connection point 80.
Also connected to PSTN 300 is calling line identification (CLI) server 350. Modern telephone networks implement a caller identification function, often referred to as CLI. The idea behind CLI is that a called party's telephone can be provided with the number of the calling party's telephone during the ringing phase, i.e. before the called party has answered the call. In FIG. 1, this function is provided by CLI server 350 which conventionally provides an interface to the 20CN access network.
Service providers can exploit the CLI server to support a simple ring-back test. This works by dialling a special, non-geographical number on the user's telephone which is detected by the local exchange and routed to the appropriate CLI sever as a ring-back request. The request includes the DN associated with the user's telephone connection. The CLI server responds, once the call has been terminated on hanging up the user's telephone, by calling back the user using the DN received with the request. An automated version of this simple ring-back test is implemented on BT's 20CN to provide an in-life check on the correct operation of a user's apparatus and associated parts of the 20CN access network. The originating Line ID (OLID) test is an automated version of the simple ring-back test that can be performed under control of test controller 170 via 20CN test head 260 connected at RCU 210. A manual version of the OLID test is available from the user's telephone.
To initiate an OLID test, an engineer supplies a request, together with the DN relating to the access line to be tested, to the test controller GTC 170. GTC 170 then acts to control the 20CN test head 260 to run the test, accessing the 20CN via test head 260 and RCU 210.
Other tests, known as in-life or BAU tests, have been developed for testing everyday operation of 20CN 200. The BAU tests involve using 20CN test equipment 260 connected at the RCU 210 to test the 20CN access network 200. 20CN test equipment 260 can run tests to check line voltage and detect dial tone on a user's connection from RCU 210.
There is a need for new tests to check the connection and operation of pairs of circuits, one from the 20CN and the corresponding one from the 21CN and to allow configuration data for these circuits to be verified. Configuration data may be stored in a database or in two separate databases: one for 20CN and another for 21CN configuration data.
The present invention provides a method of testing a first telecommunications access network and a second telecommunications access network, in which the method includes the steps of: sending a first request from a test point on the second access network to a server via the first access network; in which the first request comprises a parameter associated with a user line; in response to the first request, receiving a first identifier from the server; sending a second request from the test point through the second access network to a server; in which the second request also comprises the parameter; in response to the second request, receiving a second identifier from the server; and carrying out a comparison operation involving the first and second identifiers received in response to the two requests.
The comparison operation is preferably performed in test equipment forming part of the second access network.
According to one aspect, the method includes connecting the test point to a distribution frame connected to the first access network. According to further aspects the comparison operation includes comparing, the first identifier with the second identifier and/or the comparison operation includes comparing, the first and second identifiers with the parameter and/or the parameter is a directory number allocated to the user.
According to a further aspect the second access network is for connecting a user line transferred from the first access network.
According to a further aspect, the method includes checking access network configuration data.
According to a further aspect, the method includes using test equipment comprised in the first access network to a perform further tests and preferably using the first access network test equipment to draw dial tone from first access network equipment in order to diagnose fault conditions. Preferably, the first access network test equipment is used to test a line from the first access network equipment in order to diagnose fault conditions.
According to a further aspect, the method includes operating a test access matrix connected in the second access network between the user and a central telecommunications network to connect the second access network test equipment towards the user for the first request and towards the central telecommunications network for the second request.
The present invention also provides a test system for a first telecommunications access network and a second telecommunications access network, comprising test equipment for connection via an access arrangement to the first and second access networks; in which the access arrangement is arranged to connect the test equipment to the first access network for sending a first request from the test equipment to a server via the first access network; in which the first request comprises a parameter associated with a user line; in which the test equipment is arranged to receive in response to the first request a first identifier from the server; in which the access arrangement is arranged to connect the test equipment to the second access network for sending a second request from the test equipment through the second access network to a server; in which the second request also comprises the parameter; in which the test equipment is arranged to receive in response to the second request a second identifier from the server; and in which the test equipment is arranged to carry out a comparison operation involving the first and second identifiers received in response to the two requests.
The test equipment is preferably arranged for operation in the second access network and may include means for checking access network configuration data.
According to a further aspect, the access arrangement is arranged to connect the test equipment to a distribution frame connected to the first access network.
According to further aspects the comparison operation includes comparing, the second identifier with the first identifier and/or comparing, the second and first identifiers with the parameter.
According to a further aspect, the second access network is for connecting a user line transferred from the first access network.
The test system is preferably arranged to use test equipment comprised in the first access network to perform further tests and may be arranged to use the first access network test equipment to draw dial tone from first access network equipment in order to diagnose fault conditions and/or to test a line from the first access network equipment in order to diagnose fault conditions.
The access arrangement is preferably arranged to be connected in the second access network between the user and a central telecommunications network to connect the test equipment towards the user for the first request and towards the central telecommunications network for the second request.